so lets do it algebraically Arthur = X each twin therefore must = X + 4 ( Arthurs age plus 4) and because there's two of them it would be 2x + 8. (X + 4 but in two lots) SO putting it all into an equation it would be, X + 2x + 8= 77
we minus the 8 to equal 69 so 3x = 69 / both by 3 x= 23 and obvs the twins would 27
Arthur's twin sisters are 4 years older than him. Altogether their ages add up to 77. How old is Arthur?
i would use simultaneous equations, so say that arthur is a and the twins are each t, you can use the equations: t-a=4 2t+a=77 then add the equations together so that -a and a cancel out, so you get 3t=81 t=27 then plug 27 into the first equation, so 27-a=4 a=23